Rick Owens is face to face with a life-size wax sculpture of himself, staring out of shredded wadding and packed in a wooden crate in a corner of his London store. It's an oddly unnerving sight, as the cult Californian designer is first to admit: brown-eyed and eerily close in appearance to the man himself, the look of it is made no less disturbing by the fact that it is severed from the waist down – it has no legs.

Owens objects for less obvious reasons: "It's not nearly disgusting enough," he muses, in his west-coast American drawl. "It's been prettified." It's true that the object in question is somewhat vanilla when compared to the living, breathing man. Owens' mother is Mexican-born and his olive complexion and aquiline profile reflects that. His replica appears, somewhat bizarrely, to have rouged cheeks and lips that might not unreasonably be described as rosy. "And the eyelashes are too curled," he says, matter-of-factly. "I'll have to cut them."

Eventually, this doppelganger will reside in Tokyo, where it will be blessed "with a Godzilla tail". There's one destined for Korea, too. In that case, a wind machine will ensure that "its hair goes crazy". The original Rick Owens waxwork, meanwhile, takes pride of place in his Paris boutique."Now, that one really is horrible," Owens says with pride. When it first went on display at the Pitti Immagine fashion fair in Florence in January 2006, it caused something of a sensation, not least because it portrayed the designer, hanging from the ceiling, jeans lowered, urinating on to a mirrored floor. Today, and perhaps given the relatively bourgeois retail environment that it calls home, the bottom half is draped in black cloth, though anyone visiting may lift its skirts, should they so desire.

The project was initially a personal one. In 2003, Owens moved into a five-storey mansion in the seventh arrondissement of Paris where he lives and works in dilapidated splendour with his now wife and partner of more than 20 years, Michèle Lamy. The grand house, he says, demanded "something special". And so Owens came to London and, specifically, to the artisans employed by Madame Tussauds. "I came three times, like for fittings. There were lots of photographs, and measurements of my body, and my face. I sat there, and the sculptor is feeling my face, and working on the clay. It was so intimate, and quiet. I could see angles of my mother and father that I didn't know I have. It really was very moving."

And it was a rite of passage, he argues, warming to the formality of the subject. "At a certain point in his life," Owens says, "when he reaches a level of stature, a man commissions his portrait to go over the fireplace. It's a classical tradition, but I thought I'd do it in wax because that's funnier. It's my Dorian Gray moment."

Almost a decade later, Owens is this time in London to oversee the most recent expansion of his empire. As always, he is wearing his own designs, specifically layered fine-gauge cashmere and jersey T-shirts with "drippy" necklines and raw edges, equally louche cropped dhoti pants, the crotch of which reaches a little above his knees, and huge black leather trainers.

He once said he wanted to get intimate with Iggy Pop – he is bisexual, and put it less euphemistically than that, but pity his poor parents. His appearance is often compared to Iggy's and it's easy to see why, although Owens is a larger man.

On the day we meet, Lamy, who is French, is in attendance – she, too, is dressed head-to-toe in Rick Owens, accessorised with armfuls of bangles and signature wedge-heeled boots. She holds out her hand to reveal tattooed fingers and, when she smiles, there's a flash of gold-plated front teeth. Last year, Owens said in an interview: "In the beginning I made a point of bringing up my sexuality because I wanted to do it before anyone else could. I was with Michèle and hated the idea of someone whispering to her, 'You know, I think your husband's gay'. I was going to say it first. I didn't want anyone to think they could embarrass me, or Michèle." In a 2008 New Yorker profile, he described Lamy as "a mesmerising sphinx. I'm fascinated by someone who acts completely on instinct and feelings, where I'm so pragmatic and sensible and kind of, compared to her, boring and conservative."

The store smells of fresh paint but has an unassuming look about it – all raw concrete blocks planted with pewter clothing racks, and muted, though noticeably luxe, carpets and walls. This latest extension of the Rick Owens brand is empty save for a cellophane-wrapped glass display-case containing a neatly positioned row of mink rabbits. They're actually purses, and a far cry from the requisite logo-emblazoned accessories the designer-fashion industry is known for – sweet, but sinister at the same time. They will soon be joined by the rest of Owens' bespoke fur collection, the most upscale side of his business and taken care of by Lamy. Between 2003 and 2006, Owens was responsible for the creative direction of Revillon, a luxury goods company founded in the 18th century, and historically to animal skins what, say, La Maison Lesage is to embroidery.

"It's kind of like asking a gypsy to organise a war with a fascist," Owens says of his working relationship with Lamy. "She's so generous and flexible with deadlines and I'm not. She's the couture element. When people spend that much money, they want to come to the atelier, to get something fitted. It's also about working with artisans, about temperaments and personalities. We work with a master furrier who's incredible but eccentric. You turn around and he's making a special box for his pins and it has whiskers on it. I don't have the patience for that. I mean, he's incredible, but he's a freak."

His self-proclaimed pragmatism aside, the impression is that this is among the highest accolade Owens can bestow upon a person.

In a fashion climate ruled by luxury-goods conglomerates and an excess of merchandise that is both overwhelming and, increasingly, banal, Owens' less-than-conventional career trajectory – his business turned over more than $50m last year – is an inspiration. He doesn't advertise and his twice-yearly men's and women's collections, both shown in the French capital, are more of a development of his chosen aesthetic than a radical about-turn. While his price-tags rival that of any other designer name, Owens is less than reverent in his treatment of haute materials, actively encouraging the finest cashmere to ladder or silk chiffon to fray. His colour palette is monochrome and all the shades of "shadow" and "dust" in between.

"I try to make clothes the way Lou Reed does music, with minimal chord changes," he has said. "It's about giving everything I make a worn, softened feel. It's about an elegance being tinged with the barbaric, the luxury of not caring."

"I like classicism," he continues today. "I like historic reference. I like something new with something almost ancient. I like [legendary costume designer] Adrian; Hollywood in the Twenties and Thirties. I like discipline and the idea of restraint. I was always anti the whole moving-and-manipulating-the-body-around. It's like telling someone that their body isn't right and needs to be redone. When I make clothes it's about using bias cut, jersey and drape around the body. It has always been important to me that the clothes are somehow affectionate."

Rick Owens was born in Porterville, an agricultural town not far from Los Angeles, in 1962. He was an only child; his father is a retired social worker, his mother worked as a schoolteacher and is an expert seamstress. They are now 89 and 78 respectively, and travel to Paris to see all of their son's shows. Owens went to the local Catholic school where, he says, he was "a very sheltered, very thin-skinned, super-sensitive little boy. It was hard, it was very hard. I mean, the other kids were vicious, like animals. It still makes me angry thinking of a nice little kid going into that environment..." He pauses for thought before adding, deadpan: "I could totally have gone Columbine over there."

Any difference between Owens and his classmates wasn't helped by the fact that his father refused to allow a television into the family home until his son was 16. Instead, he listened to music – Wagner, Mahler – and read profusely and precociously – Aristotle, Confucius, Karl Huysmans, Pierre Loti.

"I have a conflicted relationship with my parents," Owens says now; something of an understatement, as it turns out. "They're great – my mother is a walking hug. But it's complicated. Dad's very homophobic. He can be very racist. He is anti-abortionist. And he's active politically in all of these things. I am an obvious reaction to that. Obviously. Spectacularly. But there's also this side of him that is very gentle. He's a very loving spirit. It's difficult to figure him out because you're thinking, 'You're a Nazi but you're so sweet'. I resented it as I was growing up, resented my dad for too much control, but he turned me into this. I advocate any kind of sexuality. I'm liberal. I'm anti-conventional. And, to keep me in his life, he has turned a blind eye to all of that."

After school, Owens went to the Otis College of Art and Design in LA, but dropped out after two years. "It was too expensive," he has since said, "and I didn't really see a job ahead". He also claims to have not had the intellectual stamina to survive in that milieu. Whatever, he ended up learning how to cut patterns "with all these Korean ladies: not glamorous. I didn't grow up in the industry, like Marc Jacobs, or Halston. I worked for knock-off companies in LA. I knocked off patterns for years."

In retrospect, this taught him the tools of his trade. Unlike many designers working in the industry today, he cuts all his own patterns. They are complex and highly abstract. "You can't convincingly get abstract until you really know the fundamentals," Owens told The New Yorker. "It's the same thing with pattern-making. You can't start distorting things unless you kind of know what you're doing."

At the end of the Nineties, Owens, by then an integral part of the Los Angeles subculture, began making clothes for himself and his friends. A washed leather jacket with ultra-long, skinny sleeves – they have ribbed wool panels along the inner arm ensuring they cling just so – a bias-cut skirt with a long, asymmetric train and narrow T-shirts in suitably sludgy shades.

Lamy, who at the time owned and fronted Café Des Artistes, one of the city's most celebrated night spots, wore his clothes. So did Courtney Love. Owens christened his signature look "glunge" – a grunge/glamour hybrid – made clothes at home and then drove around selling them to retailers himself.

"There was this little club of pioneers," Owens says. "In LA it was [buyers] Charles Gallay and Tommy Perse and there was Joyce Marr from Hong Kong, Maria Luisa in Paris, Mrs Burstein in London. Charles was the first one though. He also bought most of [Martin] Margiela's first collection, Mugler, Montana, Azzedine Alaïa."

Visionary indeed, Gallay paid for half of Owens' collections up front, becoming an unofficial patron and enabling him to produce the next one and Rick Owens sold. By this time, Lamy had bought a second restaurant – Les Deux Cafés – located in a former crack house and the two were living together in drug- and alcohol-fuelled decadence inspired, Owens says, by Baudelaire, Tennessee Williams and "just this whole idea that a candle that burns at both ends might burn shorter, but it burns brighter. Originally I was going to be like Charles James. I was going to make beautiful things and live in glamorous squalor on Hollywood Boulevard and die the hero for having stuck to my vision and not compromised."

Instead, and following an editorial featuring Kate Moss in a Rick Owens jacket in French Vogue in 2002, the designer came to the attention of American Vogue's Anna Wintour, who sponsored his first runway show in New York.

"I wasn't under a rock but I didn't know magazines, I didn't know that whole world. I admired it, but it wasn't part of my thing. I wasn't stupid. I knew which stores were the right ones and where I wanted to be, but I just thought 'I'm in a different niche of the business'. It was weird because you don't turn something like that down, but my aesthetic is so narrow, so unflamboyant, so specific, so grey."

Rick Owens was also among the most coveted insider labels of the day. Then – and indeed now – collections sold out almost instantaneously. And while other independent designers were quick to sell their businesses to fashion giants LVMH (Louis Vuitton Moët Hennessy), the Gucci Group and more, Owens secured backing courtesy of the Italian sales agency EBA, then representatives of European names including Olivier Theyskens and Ann Demeulemeester. President Luca Ruggeri and his sister-in-law Elsa Lanzo, now Owens' commercial director and CEO respectively, moved manufacture and distribution to Italy and Owens and Lamy relocated to Paris. They've both been clean – and serene, as it goes – for more than 10 years .

"There was a heavy dose of self-destruction in there," Owens says of his former life, "because of shame and about having been so much of an outsider and rejected early on in a small town. I think it had to do with fear. I guess I grew out of it. You get older. You figure it out. And also I just got scared. It went too far and, really, I could feel myself dying."

The "history of the damage" is still central to his creative output, he says. "Definitely. And there's a lot of self-acceptance in it, too, because I don't punish myself any more for having made mistakes. I don't punish myself for not having been perfect. It all happened for a reason. It was all fine. I'm fine. I'm not perfect and I don't have to be. And neither does anyone else."

As driven as he is considerate, and as raw as he is extremely refined, Rick Owens, the person, is perhaps his most magnificent construct. A "workaholic", responsible for his men's and women's main line, the more accessible Rick Owens Lilies and Drkshdw, and now fine-fur, and furniture collections, he says that he found the runway experience difficult to begin with.

"I cringe when I look at the early Paris shows because I was trying to entertain, to be something I'm not. We know how to do it now."

Moving forward discreetly with the zeitgeist, the mainstay of Owens' business – the languid silk "flow" pants, the ultra-soft and skinny sweaters, the proud-to-be-droopy shorts that resemble nothing more than nappies, the dignified draped, bias-cut gown and, of course, the oft-emulated washed leather jacket – remains the same. The designer works out, eats well and "hates holidays – I get antsy". Rick Owens is still something of an outsider, working with a skeleton team and, principally, with Lamy, in splendid isolation, although the latter continues, on occasion, to give good party.

"We're people who have been given an opportunity to express ourselves and to create," he says. "This is after years of reading, years of exploring, years of self-destructing. Especially as a reflection of the latter, this is the opposite of that. This is composing, making something instead of degenerating and why wouldn't I want to commit to that? I'm not taking it for granted. I'm lucky because I was in the right place, with the right people, at the right time. That kind of opportunity doesn't come along very often so, as long as you have it, take full advantage. I truly love what I'm doing."